TW201942292A - Silicon-based protective film for adhesive, method of production thereof and uses thereof - Google Patents

Abstract

Silicon-based protective film for adhesive or self-adhesive elements, characterized in that said protective film is based on silicone and has a level of extractible silicone less than or equal to 100 ng/cm2, preferably less than or equal to 50, preferably less than or equal to 20 ng/cm2, and even more preferably less than 10 ng/cm2, the method of production thereof and uses thereof.

Description

Silicon-based protective film for adhesive, manufacturing method and application thereof

The invention relates to a silicon-based protective film for an adhesive or a self-adhesive, especially based on polysiloxane, and more particularly based on polysiloxane, optionally including a paper or plastic substrate having at least one release coating, and Concerning an assembly comprising an adhesive or self-adhesive element and at least one protective film as indicated above.

Adhesives can be of various types. In electronic applications, adhesives are generally based on acrylates, but are not limited thereto, and are preferably electronic grade. In other cases, external films (such as those attached to touch screens before use) have adhesive or self-adhesive features through polysiloxane adhesives. In other applications, such as in medical devices, the adhesive or self-adhesive is exactly a polysiloxane-based and especially (but not limited to) medical grade adhesive or self-adhesive.

The invention further relates to its use and its manufacturing method.

In a first aspect, the invention therefore relates to a silicon-based protective film for an adhesive or a self-adhesive component.

Adhesives or self-adhesive elements can take various forms. Between the adhesive or self-adhesive element including the first or self-adhesive side and the second side that is not an adhesive, and the adhesive element including the first and second sides having the properties of the adhesive or self-adhesive Make a distinction.

These adhesives are preferably pressure-sensitive adhesives or self-adhesives, and have different properties depending on their application. In electronics, the adhesive will have acrylic / acrylate properties, while medical fields generally prefer polysiloxane adhesives or self-adhesives. It has excellent heat and cold resistance, electrical insulation properties, and is particularly safe and reliable. Silicone-based pressure-sensitive adhesive tapes are easy to remove and have good adhesion characteristics over a wide range of surfaces. It can be found in, for example, adhesives for masks, special adhesives, protective films, double-sided tapes and labels.

Silicone-based adhesives or self-adhesive medical devices for medical use can have various forms, such as adhesive electrodes, patches and intradermal adhesives and adhesives or self-adhesive dressings intended to be placed on the skin.

For adhesive or self-adhesive components that include the first and second "non-adhesive" surfaces with adhesive or self-adhesive properties, the adhesive or self-adhesive coating can be applied to various types of substrates (such as paper ) To form labels, plastic or polymer substrates, woven or non-woven substrates, and medical devices such as medical dressings.

When commercially available adhesives or self-adhesive components are substantially flat, they are generally coated on a "non-stick" substrate, that is, on a paper or plastic or polymer-based substrate coated with a non-stick coating. on. These substrates with non-stick coatings form a protective film in the form of a peelable layer (known as a "release liner") that is attached to many polysiloxane-based adhesives or self-adhesive components, such as Based on many polysiloxane based adhesives for medical use or self-adhesive medical devices.

Therefore, there are various applications of silicon-based protective films for polysiloxane-based adhesives or self-adhesives, such as for medical applications.

When these adhesives or self-adhesive components are rolled into adhesive rolls, some medical dressings, and protective film rolls are sold, they can (but not always) be coated on "non-stick" substrates. Sometimes, the adhesive or self-adhesive surface is placed on the second non-adhesive surface of the adhesive component. In this case, the non-stick coating forming the protective film may be directly coated on the second "non-stick" surface of the adhesive or self-adhesive component before or after it is coated with the adhesive or self-adhesive.

For adhesives or self-adhesive components (double-sided adhesives or self-adhesive components) that include the first side with adhesive or self-adhesive properties and the second side with adhesive or self-adhesive properties, the adhesive or The self-adhesive coating is applied to various types of substrates, such as paper, plastic or polymer substrates, woven or non-woven substrates, or even to a protective film before attaching the substrates thereto.

When commercially available double-sided adhesives or self-adhesive components are substantially flat, they are generally positioned between two "non-stick" substrates, that is, paper-based or plastic-based or polymer-coated non-stick coatings. On the substrate. These non-stick substrates form a protective film in the form of a peelable layer (called a "release liner"), which is attached to many adhesive components.

When these double-sided adhesives or self-adhesive components are rolled into adhesive rolls, some medical dressings, some protective film rolls are sold, they can be coated on a "non-stick" substrate, which will A substrate comprising a non-stick coating on both sides of the substrate forming a protective film (also in the form of a peelable layer).

Therefore, there are many applications for silicon-based protective films for adhesives or self-adhesive components.

In the sense of the present invention, a surface with low adhesion will be referred to as "non-stick". This adhesion is characterized relative to a second surface that is in contact with a surface with low adhesion.
[current technology]

Silicon-based protective films for adhesive components coated on substrates are known to us, such as films for temporary protection of adhesives, which generally consist of a polysiloxane layer. This polysilicon layer produces substrate characteristics with weak adhesion. The latter makes it possible to protect the adhesive before it is applied to the object. The polysiloxane layer can be chemically deposited in the liquid phase (wet chemical deposition) by thermally or UV-crosslinking on the surface of the substrate (paper or plastic), chemically deposited with the aid of a plasma. In the gas phase (plasma-assisted chemical vapor deposition), by reactive deposition of a compound or monomer containing fluorine and / or silicon, deposition by powder coating (powder coating).

Unfortunately, these conventional films for temporary protection of adhesives are not available in certain electronic applications, such as touch screens for hard drives or positioning with optical-grade adhesives, for example. Use because the polysiloxane coated on the substrate is partially transferred to the adhesive and unacceptably contaminates the latter due to its interference with electronic components.

Polysiloxane-based protective films for adhesives or self-adhesive medical devices that are coated on a substrate for medical use are known, such as films for temporary protection of adhesives, which are generally made of polymer Silicon oxide layer composition. However, these films for temporary protection of adhesives are only compatible with acrylic adhesives or rubbers.

Fluoropolysiloxane-based protective films for adhesives or self-adhesive medical devices coated on substrates for medical purposes are known, such as for temporary protection of polysiloxane-based adhesives, for example. membrane.

This polysilicon or fluorosilicon layer produces substrate characteristics with low adhesion. The latter makes it possible to protect the adhesive before it is applied to the object or body. The polysiloxane layer can be chemically deposited in the liquid phase (wet chemical deposition) by thermally or UV-crosslinking on the surface of the substrate (paper or plastic), chemically deposited with the aid of a plasma. In the gas phase (plasma-assisted chemical vapor deposition), by reactive deposition of a compound or monomer containing fluorine and / or silicon, deposition by powder coating (powder coating).

The most commonly used treatment technique consists of wet deposition based on polysiloxane coatings. This type of treatment is performed in two steps. The first step of the treatment consists of a sedimentation emulsion, and the second step consists of the surface coating formed by drying. The polysilicon layer thus formed also imparts low adhesion properties to the substrate, thereby allowing the adhesive to be protected before being applied to the object.

Unfortunately, this type of processing encounters many problems and can be, for example, as follows: The deposition method is sometimes long and requires many intermediate steps. There are high-energy expenditures. Some chemical treatments based on silicone coatings involve organic solvents and are therefore not environmentally compatible; others use aqueous emulsions with emulsifiers that have the risk of transferring to adhesives. When a substrate having such a surface coating is used as a substrate for an adhesive, for example, as a substrate for a label, there is a clear possibility that, for example, a polysiloxane material is transferred to the adhesive, which has the effect of reducing its adhesiveness. The effect of nature, or the obvious possibility of transfer to any surface in contact with the coating, has the effect of causing unwanted contamination.

Alternatively, in the presence of self-adhesive elements, such as polysiloxane-based self-adhesive elements, the transfer of polysiloxane materials from the protective film to the self-adhesive elements can reduce their adhesion on the one hand, but can also be used with adhesives. Or the silicon-based material of the self-adhesive component reacts. In fact, silicified adhesives or self-adhesive components are formed by cross-linking agents, catalysts, and polysiloxanes, and the reaction is usually not complete. In this case, the transfer of polysiloxane materials to self-adhesive components can cause uncontrolled and / Or undesired reaction products. This is due to the chemical bond between the silicon-based adhesive or self-adhesive and the protective film, which reduces or even eliminates its peelability. This is more accurately used in medical devices in the medical field. the field represents a major drawback, especially annoying (see the article "Release liner Selection for drug delivery and Medical device design " -Engineering 360 Media Solutions 2017 Nian August).

This applies to both protective films and medical devices used in the electronics industry, such as dressings, patches and electrodes to be applied to the skin. In the latter case, an uncontrolled reaction can cause an immune or allergic reaction, or the incompatibility of the product with the medical field. In addition, the release of the polysiloxane material from the adhesive element forming the dressing can release the polysiloxane material into the wound under the dressing, which is of course undesirable.

Therefore, in the medical field and the field of electronic components to avoid the contamination of polysilicon, a protective film with low polysilicon release is generally required in order to avoid reducing the adhesive quality of the adhesive component, and the polymer-based polymer for medical use is also specifically required. Silicone adhesive or self-adhesive medical device. In fact, the pollution of finished electronic components by tags, the pollution of clean room atmosphere, the contamination of wounds by polysilicon, or the self-adhesive substrate and the polysilicon that may be released from the protective film. The occurrence of controlled reactions is completely undesirable.

There are also films for temporary protection of adhesives without polysiloxane. Although these silicone-free films do not present the risk of polluting the environment or having silicone adhesives, they unfortunately have excessive peeling force and have a "zippy" effect that is offensive to users (impulse Peeling).

The present invention provides a silicon-based protective film for an adhesive or a self-adhesive component as mentioned at the beginning, more specifically based on polysiloxane, especially based on polysiloxane, characterized in that the protective film is based on polymer Siloxane has non-volatile (IDEMA standard M7-98 "Organic Contamination as Nonvolatile Residue (NVR)"",ECSS-Q-ST-70-05C" Detection of organic contamination of surfaces by infrared spectroscopy ", Seagate 20800032-001 Rev C. & 20800014-001 Rev G, Western Digital 2092-772141 Rev AD & 2092-771888 Rev AC) or volatile (IDEMA standard M11-99 `` General Outgas Test Procedure by Dynamic Headspace Analysis '', Seagate 20800020- 001 Rev N, Western Digital 2092-001026 Rev AC & 2092-771888 Rev AC) The amount of polysiloxy released in the form of monomer or oligomer is less than or equal to 100 ng / cm ² , preferably less than or equal to 50 ng / cm ² , more preferably less than or equal to 20 ng / cm ² , and even more preferably less than 10 ng / cm ² , and preferably less than 5 ng / cm ² of extractable polysiloxane content.

For example, it can be a polysiloxane-based adhesive for medical devices or a self-adhesive medical-grade polysiloxane-based protective film, and, for example, will be opposed to a drug substance that will diffuse through the adhesive Inert.

In fact, it becomes apparent according to the present invention that it is possible to provide a protective film in which the transferred contamination is particularly low, while providing the possibility of relying on polysiloxanes with improved peel characteristics without having to use organic or fluorine that produces other difficulties化 Molecules.

In addition, the use of a polysiloxane-based protective film advantageously allows imparting hydrophobic characteristics to the substrate on which the protective film is attached, thereby making it usable in fields such as electronic components and medical departments, and maintaining the quality of adhesive components over time.

The silicon-based protective film for an adhesive or a self-adhesive element according to the present invention has both low surface energy and low adhesion (so-called "release" effect), is simultaneously hydrophobic, and hardly releases any extractable Polysiloxane. The unique combination of these features of the protective film according to the present invention therefore makes it suitable for use in areas with high demand (such as the electronic component sector), which is made by the protective film (hydrophobic non-stick substrate) and the substrate Adhesives between self-adhesives or self-adhesives (such as labels, tapes or dressings, patches, electrodes or dressings), but also especially suitable for pressure-sensitive adhesives and self-adhesives based on silicone.

According to the present invention, when measuring the content of extractable polysiloxane, we measure the measured surface sample of the protective film washed with hexane (IDEMA standard M7-98 "Organic Contamination as Nonvolatile Residue (NVR)", Or standard ECSS-Q-ST-70-05C "Detection of organic contamination of surfaces by infrared spectroscopy", Seagate 20800032-001 Rev C. & 20800014-001 Rev G, Western Digital 2092-772141 Rev AD & 2092-771888 Rev AC ) Or by degassing the measured surface sample of the protective film (IDEMA Standard M11-99 "General Outgas Test Procedure by Dynamic Headspace Analysis", Seagate 20800020-001 Rev N, Western Digital 2092-001026 Rev AC & 2092-771888 Rev AC) The amount of polysiloxane (especially in the form of a monomer or oligomer) that is subsequently released.

The protective film according to the present invention is a protective film that can be applied to an existing substrate, such as a surface of an existing tape, or can include a substrate made of paper, woven or non-woven product, or plastic.

In a preferred embodiment of the present invention, the silicon-based protective film for an adhesive or a self-adhesive component has a NSA of less than or equal to 2 N / 25 mm measured on a Tesa ^TM 7475 adhesive measured according to the standard FTM10. Peeling force.

In another preferred embodiment of the present invention, the silicon-based protective film for an adhesive or a self-adhesive component has a residual adhesion greater than or equal to 80% as measured according to the standard FTM11.

The film according to the invention has the characteristic that it does not impair the effectiveness of the adhesive or self-adhesive. Residual adhesion, that is, the adhesive force of the adhesive after being exposed to the film for temporary protection of the adhesive is greater than or equal to the initial force of the adhesive (before contact with the film for temporary protection of the adhesive) 80%.

In another preferred embodiment of the present invention, the silicon-based protective film for an adhesive or a self-adhesive element has a nitrogen content of less than or equal to 1 atomic% (atomic%) as measured by the XPS / ESCA technology.

These values are self-measured in a normal detection (detection angle θ = 0 °) over a 300 µm x 700 µm area with a Nova-Kratos ™ type device with a monochromated Al-Kα source (225 W) Spectral determination. The depth of analysis under these conditions is less than 10 nm.

In a variation according to the present invention, the silicon-based protective film for an adhesive or a self-adhesive element is formed of a series of polysilicon-based layers deposited on top of each other.

Advantageously, in the silicon-based protective film for an adhesive or a self-adhesive element according to the present invention, each polysiloxane layer has between 5 nm and 100 nm, preferably between 10 nm and 60 nm and even Better thicknesses between 10 nm and 30 nm.

Preferably, the silicon-based protective film for an adhesive or a self-adhesive element according to the present invention has between 5 nm and 100 nm, preferably between 10 nm and 60 nm, and more preferably between 10 nm and 30 nm. Between thickness.

In fact, if the thickness of the polysiloxane layer is insufficient, the layer unevenly covers the substrate, which results in an increase in peel force and lively effect; if the thickness is excessive, the risk of contamination and / or transfer increases, because the total amount of polysiloxane The amount becomes too large (knowing that in the worst case the total amount of polysilicon that can be transferred is proportional to the thickness of the layer). The preferred thickness is between 10 nm and 60 nm, and even more preferably between 10 nm and 30 nm. Below 5 nm, the deposits are non-uniform, which causes unwanted jerking off (active effect). In addition, when the thickness is too small, the adhesion increases. Above a thickness of 30 nm, the required quality of the layer is not further improved, but the total amount of polysilicon that can be transferred becomes unnecessarily large.

In a specific embodiment of the invention, the silicon-based protective film for an adhesive or self-adhesive element has a static contact angle of at least one water, as measured on the device Krüss DSA25, greater than 90 °, preferably greater than 95 °, and Even better surfaces larger than 100 °.

In another specific embodiment of the present invention, the silicon-based protective film for an adhesive or a self-adhesive element has a measurement result from a contact angle of two liquids (water and diiodomethane) according to a model of Owens and Wendt, for example. The calculated surface energy is less than 30 mN / m, preferably less than 25 mN / m and even more preferably less than 20 mN / m.

The present invention also relates to an assembly comprising at least one silicon-based protective film for an adhesive or a self-adhesive component according to the present invention, and an adhesive or a self-adhesive having a first surface having an adhesive or self-adhesive property element.

More specifically, in the assembly according to the present invention, the protective film in the form of a protective film attached to the first side having the characteristics of an adhesive or a self-adhesive is peelable.

Even more preferably, in the assembly according to the present invention, the adhesive or self-adhesive element has a first surface and a second non-adhesive surface having adhesive or self-adhesive properties, and the protective film is attached to the second Not sticky.

In a modification of the assembly according to the present invention, the adhesive or self-adhesive element has a second surface having the characteristics of an adhesive or self-adhesive, and a second silicon-based protective film is attached to the second surface as appropriate.

In another embodiment according to the present invention, the adhesive element is a label.

In yet another embodiment according to the present invention, the adhesive element is an adhesive or a self-adhesive medical device, and is an adhesive or a self-adhesive medical dressing, such as a silicide, a patch, or an adhesive electrode intended to come into contact with the skin.

The present invention also relates to a method for manufacturing a silicon-based protective film for an adhesive or a self-adhesive component having at least one polysiloxane-based coating intended to be placed on paper, woven or non-woven or plastic substrate Floor.

Methods for manufacturing protective films for adhesives or self-adhesive components are known from the prior art.

For example, from document WO 2016/071 256, a plasma is known that uses a low frequency reactor (2 kHz to 100 kHz) and a pulsed AC voltage of 5 kV to 50 kV at a switching frequency between 30 Hz and 5000 Hz Approach. In contrast to treatment with conventional plasma (without pulses), these pulses make it possible to induce improvements in the characteristics of the release layer.

Document WO 2016/071 256 describes a protective film comprising a substrate and a release layer, which is based on a long list of polysiloxane-based and also other molecules such as fluorinated alkanes and polyolefins, urethanes, waxes and mixtures thereof ) Of compounds. Documents WO 2015/019063 or WO 2015/019062 describe similar protective films.

However, this document does not describe the extractable polysiloxane content from the polysiloxane-based protective film used for the adhesive, and the residual adhesion of the adhesive after the protective film is separated.

Therefore, there is still a need to identify a method for making a silicon-based protective film for an adhesive or a self-adhesive component with a low extractable polysilicon content.

The present invention relates to a specific field that allows the surface of a substrate to exhibit hydrophobic and non-stick surface deposits. There will be a need for a novel method for efficiently performing the deposition of a coating with hydrophobic characteristics on the surface of a substrate, which has both low surface energy and low adhesion (the so-called "release" effect), while simultaneously solving The problems mentioned above are encountered in existing methods for surface treatment. In fact, in several technical fields, especially in the field of adhesive films, these two features are advantageously combined, which allows a hydrophobic non-sticky substrate (that is, a substrate obtained after the surface treatment method according to the present invention) and Adhesive substrates, such as silicone-based labels or adhesives for medical applications or controlled reduction of adhesion between self-adhesive medical devices. In addition, it must be possible to perform this method while moving the plastic film.

The method according to the invention is characterized in that it comprises the following steps:
a) traveling the substrate from the substrate source in a plasma coating unit to form the protective film, until the collection point of the protective film,
b) exposing the first side of the substrate to plasma deposition in a chamber in the presence of at least one polysiloxane precursor selected from siloxanes containing cyclic feature groups, the presence of at least one Plasma gas and an atmosphere consisting of a discharge controlled by a dielectric barrier (DBD) of the plasma gas selected from a rare gas or a mixture thereof,
c) forming the polysiloxane-based coating from the polysiloxane precursor in the plasma, and
d) collecting the protective film provided with the at least one polysiloxane-based coating.

This problem is solved according to the present invention by a method of surface treating a mobile substrate, especially a flexible or semi-rigid polymer film or paper that passes through a processing area. More precisely, it is a method of subjecting a substrate to a plasma generated in a mixed gas, which in particular results in the modification of the surface state of the substrate by forming a deposit on the aforementioned surface.

The invention relates in particular to a method which can potentially be carried out at pressures close to atmospheric pressure and which is suitable for continuous surface treatment of polymer films in reels ("reel type" methods).

The method according to the present invention comprises the step of subjecting at least one surface of the substrate in the presence of at least one silicon precursor selected from a siloxane containing a cyclic feature group under the atmospheric pressure of a plasma gas (selected from an inert gas). Exposure to a discharge controlled by a dielectric barrier (DBD = dielectric barrier discharge, a technique known per se) to form the coating on the mobile substrate.

The film treated by the method according to the present invention has an adhesive force on its external surface (that is, the surface not in contact with the substrate) that is less than the adhesive force of the uncoated film, making it possible to adjust the adhesion by means of deposition parameters force.

The combination of an inert gas and a precursor in a plasma sprayed in the chamber to form a plasma-forming atmosphere makes it possible to obtain, especially surprisingly, a silicon-based protective film with extremely low levels of extractable substances. Siloxane containing cyclic characteristic groups.

Advantageously, according to the invention, the plasma gas is argon or helium, and preferably argon.

In one advantageous embodiment of the present invention, the polysiloxane precursor is cyclosiloxane.

In a particular advantageous embodiment of the present invention, the polysiloxane precursor is a cycloalkylsiloxane, preferably a cyclomethylsiloxane.

Advantageously, the polysiloxane precursor is decamethylcyclopentasiloxane (CAS No. 541-02-6) or octamethylcyclotetrasiloxane (CAS No. 556-67-2), hexamethyl Cyclotrisiloxane (CAS No. 541-05-9), dodecylcyclohexasiloxane (CAS No. 540-97-6) or a mixture of two or more of these.

Advantageously, in the manufacturing method according to the invention, the gas atmosphere in the chamber has an oxygen content of less than or equal to 50 ppmv, preferably less than or equal to 20 ppmv and even more preferably less than or equal to 10 ppmv.

In a preferred embodiment of the method according to the invention, the substrate is between 10 m / min and 60 m / min, preferably between 10 m / min and 50 m / min, and preferably between 20 m / min and 40 The substrate travels between m / min, advantageously between 25 m / min and 40 m / min, and very advantageously between 30 m / min and 40 m / min.

Advantageously, in the manufacturing method according to the invention, the plasma deposition has a deposition time of less than or equal to 4 seconds, preferably less than or equal to 2 seconds and even more preferably less than or equal to 1 second.

Excellently, processed in one pass without any post-processing. This helps maximize the productivity of the machine (in terms of area units processed per unit of machine time) and minimizes the operating costs of the method.

This makes it possible to obtain high-speed travel and produce extremely thin layers. High speed travel means high productivity (expressed in area units processed per unit of machine time), and therefore means low operating costs of the method. On the one hand, small thickness means lower consumption of precursor molecules per unit of surface area processed (this helps to minimize the operating cost of the method), and on the other hand, when layers are used as desired, The theoretical total amount of polysiloxane per unit surface area that can be transferred to the adhesive is low.

In a preferred embodiment of the present invention, the gas atmosphere in the chamber is at atmospheric pressure ± 100 Pa.

Here, the "pressure close to the atmospheric pressure" means that the pressure difference from the atmospheric pressure does not exceed several tens or about one hundred Pa (positive or negative). More precisely, preferably, the pressure in the chamber differs from the atmospheric pressure by at most ± 100 Pa.

In a preferred embodiment of the invention, the discharge is at a low frequency, preferably between 0.10 W / cm ² and 10 W / cm ² , more preferably between 0.15 W / cm ² and 8 W / cm ² Time, more specifically between 0.2 W / cm ² and 5 W / cm ² or even between 0.25 W / cm ² and 0.8 W / cm ² and even more preferably between 0.35 W / cm ² and 0.7 W / cm ² power density, area unit refers to the cumulative area of the electrode.

The present invention finally relates to the use of a protective film according to the present invention for an adhesive or self-adhesive element including a first surface having the characteristics of an adhesive or a self-adhesive.

In a variant according to the invention, the invention finally relates to a polysiloxane-based protective film for a polysiloxane-based adhesive or self-adhesive and a polysiloxane-based adhesive or self-adhesive according to the invention Use of components such as, for example, polysiloxane-based pressure-sensitive adhesives or adhesive medical devices containing a first adhesive side on which the adhesive is located.

In a preferred application, the protective film is in the form of a peelable protective film in contact with the first surface.

In a specific application according to the present invention, the adhesive element has a first surface and a second non-adhesive surface having the characteristics of an adhesive or a self-adhesive, and the protective film is attached to the second non-adhesive surface.

In another specific application according to the present invention, the adhesive element has a second surface having adhesive or self-adhesive properties, and a second silicon-based protective film is attached to the second surface as appropriate.

In a particularly preferred application, the adhesive element is a silicone-based label, a double-sided tape, or a pressure-sensitive protective film.

In another particularly preferred application, the adhesive or self-adhesive medical device is an adhesive or a self-adhesive medical dressing, such as a silicidation, a patch, an adhesive electrode intended to come into contact with the skin.

Preferably, the aforementioned use occurs in a clean room. In addition, the manufacturing method according to the present invention can be performed in a clean room.

In addition, the protective film according to the present invention can be sterilized by a conventional technique (γ sterilization, in a gaseous medium, UV, etc.).

Other features, details and advantages of the present invention will become clearer from the non-limiting description given below and reference examples and accompanying drawings.

Unless otherwise stated, gas concentrations given in ppm (parts per million) are ppm (ppmv) by volume.

According to the present invention, the substrate is exposed to the plasma at atmospheric pressure. Plasma is generated in a plasma gas (He, Ar) containing one or more siloxane precursors; the precursor will be designated below. The substrate is exposed to molecules of the plasma and precursors such that a thin deposit is formed on the surface of the substrate. This thin deposit gives the protective film for adhesive components low adhesion and a very small amount of extractable polysiloxane. In addition, this deposit does not significantly reduce subsequent adhesion of the adhesive to the protective film containing it.

In the method for manufacturing a protective film according to the present invention, plasma deposition at atmospheric pressure therefore makes it possible to manufacture a non-stick layer on a substrate to form a protective film (release liner).

The method according to the invention can be carried out in a reactor, within which a dielectric barrier discharge (DBD) occurs.

Advantageously, the substrate travels through the processing area in a reel mode.

In a preferred embodiment, the processing reactor is of the reel type DBD; it typically contains the following elements:
-A processing cylinder with a suitable dielectric coating (for example, having a diameter of 400 mm and a length of 800 mm). This cylinder pushes the flexible film to process at a speed selected between 5 m / min and 200 m / min under the processing electrode.
-A processing chamber located above the processing cylinder and containing the electrode and the means for ejecting the gas; the ejection means adjacent to the electrode makes it possible to eject one or more gases directly in front of the electrode and on the surface of the film to be treated, ie Inert gas, plasma gas, precursor, carrier gas, and optional doping gas.

The electrodes are connected to a low-frequency HV generator (usually one to several tens of kHz) of variable power (0.1 to 10 W / cm ² ). Power density between 0.10 W / cm ² and 10 W / cm ² , more preferably between 0.15 W / cm ² and 8 W / cm ² , more specifically between 0.2 W / cm ² and 5 W / cm ² Between, or even between 0.25 W / cm ² and 0.8 W / cm ² , and even more preferably between 0.35 W / cm ² and 0.7 W / cm ^2. The unit of area refers to the cumulative area of the electrode.

The extraction system in the processing chamber makes it possible to evacuate the plasma gas and any by-products that are generated in the plasma and have not been converted to deposits. Plasma gas produces plasma, which is a specific feature of discharge at atmospheric pressure. The carrier gas is sprayed to accompany the precursor (monomer). The dopant can be ejected in a small amount relative to the inert gas, the plasma gas, and the carrier gas. The inert gas, plasma gas and / or carrier gas may be the same or different, and may be argon and / or helium.

Advantageously, the inertized processing atmosphere is maintained in a processing reactor with an oxygen content of less than 50 ppm, preferably less than 20 ppm and even more preferably less than 10 ppm.

A reactor of this type is described in the name of the applicant in, for example, patent application WO 2016/170242.

The gap between the active surface of the electrode and the film traveling under the electrode on the processing roll must be adjusted very precisely in order to ensure the stability and homogeneity of the plasma. Necessary conditions for sediment. As an example, if the distance between the membrane and the active surface of the electrode is set to 1 mm, this distance is advantageously stable with a standard deviation of ± 0.2 mm.

The precursor is advantageously injected directly into the discharge, which makes it possible to maximize the latter concentration between the electrodes. This applies to making processing possible in a single pass. High concentrations of precursors in the discharge generally result in the formation of powders in the plasma; the products made from these powders are unusable and cause many problems in reactor maintenance. At high gas velocities, it is possible to reduce the residence time of precursor molecules in the plasma; this avoids the formation of powder. Therefore, it is possible to work under high concentration precursors, which makes it possible to deposit in a single pass without forming a powder.

It should also be noted that exposure of the formed protective film to the plasma reduces the effectiveness of the thin layer. Therefore, it is not necessarily desirable to perform the deposition in several passes.

As an example, the following parameters are used in a reactor of the type described in WO 2016/170242:
The flow rate of the precursor is preferably between 8 g / h and 14 g / h, more preferably between 8.5 g / h and 13 g / h; at the value of 10 g / h, good results are obtained , But at 5 g / h or 20 g / h, the results are worse. The substrate speed is preferably between 3 m / min and 8 m / min, preferably between 3.5 m / min and 8.5 m / min, but at the value of 2 m / min or 10 m / min, the result is Worse. The power is preferably between 450 W and 700 W, more preferably between 500 W and 650 W, but at the value of 300 W or 900 W, the result is worse. The plasma gas is preferably argon.

In the context of the present invention, the precursor should be a siloxane containing a cyclic characteristic group, such as, for example, a cycloalkyl siloxane, preferably a cyclomethyl siloxane. The inventors have unexpectedly found that linear alkylsiloxanes (and therefore no cyclic characteristic groups) do not produce satisfactory results, and use of siloxanes containing cyclic characteristic groups such as cycloalkylsilicones Oxane, and especially cyclomethylsiloxanes) make it possible to solve the problems that the present invention seeks to solve.

Advantageously, the polysiloxane precursor is decamethylcyclopentasiloxane (CAS No. 541-02-6) or octamethylcyclotetrasiloxane (CAS No. 556-67-2), hexamethyl Cyclotrisiloxane (CAS No. 541-05-9), dodecylcyclohexasiloxane (CAS No. 540-97-6) or a mixture of two or more of these.
Examples
Example 1

Surface treatment is performed by depositing a thin layer in an argon plasma at atmospheric pressure. The plasma gas is argon. The following Table 1 presents the best results obtained on a PET substrate for forming a protective film according to the present invention. Specifically, the peel force and residual adhesion of the adhesive were measured after removing the protective film of the treated PET.

Several types of organosiloxane monomers are used to make silicon-based release layer deposits at monomer ratios in the range of 100 to 10 000 ppm (by volume):
· DMCPS = Decamethylcyclopentasiloxane; CAS No. 541-02-6;
OMCTS = octamethylcyclotetrasiloxane, CAS No. 556-67-2;
OTES = triethoxy (octyl) silane, CAS No. 2943-75-1;
· HMDSO = Hexamethyldisilazane, CAS No. 107-46-0.

Two types of OH or NH-functionalized reactive polysiloxane precursor monomers (Silmer ™) are also used at monomer ratios in the range of 100 to 5000 ppm to make polysiloxane-based thin deposits. The trademarks for these monomers are: Silmer ™ NH Di-8 and Silmer ™ OH A0 UP (supplied by Siltech). It is a linear polyalkylsiloxane; more specifically, Silmer ™ NH Di-8 is a linear amino polydimethylsiloxane containing NH end groups (molecular weight of about 860 to 940), and Silmer ™ OH A0 UP is a polydimethylsiloxane (molecular weight about 280) with a propyl hydroxyl terminal function.

For comparison, a non-polysiloxane type monomer (dodecyl vinyl ether, CAS No. 765-14-0) was investigated for the preparation of silicon-free release deposits at a monomer ratio of 100 ppm. Fluoropolysiloxane type monomers are also tested.

As can be seen, the best results were obtained on a PET film having a width of 600 mm and treated with a 600 W argon plasma at 20 m / min, and 60 g / h of DMCPS was introduced into the argon plasma (the sample was weighed "DMCPS"), although pre-processing is possible, it is not necessary in this case, while allowing excellent results. Performing the same preferred method on paper and BOPP film has excellent results.

Table 1 summarizes the characteristics of the protective film measured on samples made according to the present invention.
Table 1

In this table:
-"Lively" indicates that the adhesive hastily detached from the protective film;
- θ is the measured _water in the water Krüss DSA25 means a static contact angle;
-Es is the surface energy calculated from the measurement results of the contact angles of two liquids (water and diiodomethane) according to the models of Owens and Wendt;
-Fp 7475 is the peeling force of TESA 7475 adhesive measured with AR1000 device according to standard FTM 10;
-Fp MD15 is the peeling force of MD15 adhesive (ultra-pure acrylic adhesive used in the field of electronic components) supplied by the company JDC (Tennessee, USA);
-AR Nitto 31b is the residual adhesion of the adhesive Nitto 31b measured on a glass plate cleaned according to the standard FTM 11; those skilled in the art use this adhesive to measure residual adhesion.

The standard FTM 10 and FTM 11 familiar to those skilled in the art are disclosed by FINAT (International Federation of Manufacturers and Processors of Adhesives and Heat-sealing Adhesives on paper and other substrates):
-FTM 10 "Quality of silicone coated substrates for self-adhesive laminates : release force ( 300 mm / min ) " ,
-FTM 11 "Quality of Silicone-Coated Substrates for Self-Adhesive Laminates: Subsequent Adhesion" .

Table 2 shows the measurement results (in atomic percentage) of carbon, oxygen, silicon, and nitrogen in three samples treated with plasma at atmospheric pressure. These values are self-measured in a normal detection (detection angle θ = 0 °) over a 300 µm × 700 µm area with a Nova-Kratos ™ type device with a monochromated Al-Kα source (225 W) Spectral determination. The depth of analysis under these conditions is less than 10 nm.
Table 2

It should be noted that the sample "DMCPS Argon 1" corresponds to the sample "DMCPS" in Table 1. Sample "DMCPS Nitrogen" was prepared using a nitrogen plasma containing the precursor DMCPS: this layer contains nitrogen. Its Fp value is too high. Prepare the sample "DMCPS Argon 2" under conditions similar to those used for the sample "DMCPS Argon", but with a thickness of less than 10 nm: the XPS spectrum reveals the contribution of the signal to the substrate, and The indicated concentrations therefore do not reflect the composition of the layers deposited by the method according to the invention.

For samples of plastic films treated with the monomer DMCPS by the method according to the invention, the extractable residual siloxane content was determined. In order to determine this content of residual siloxane, the treated 50 cm ² area was washed with n-hexane, and the liquid phase was concentrated on a ZnSe plate and analyzed by Fourier transform infrared spectroscopy (FTIR) (resolution 4 cm ^-1 , 8 scans, mirror speed 0.20 cm / s). Siloxane content is based on the spectral band characteristics of siloxane (such as the ECSS reference " Space product assurance : Detection of organic contamination of surfaces by infrared spectroscopy " dated March 6, 2009, section ECSS-Q-ST-70 -05C, point 21, point e., And between about 2800 and 300 cm ^-1 indicated in Table 5.1), a series of poly (dimethylsiloxane) standards, commercial from Aldrich Product, reference 378380 (CAS No. 63148-62-9) calibration intensity. The measurement results are shown in Table 3. In another procedure, the sample is heated under a constant air flow. The identity and number of molecules emitted by the sample were determined by gas chromatography and detection by mass spectrometry (see column 4 in Table 3).

Table 3 shows the measurement results of the extraction of polysiloxanes on the samples treated according to the method described above.
Table 3
Example 2

After contacting at a temperature of 70 ° C and a moisture content of 50% for 20 hours, the peeling force of the adhesive on the protective film according to the present invention (measured according to the standard FINAT 10) and that on the commercial protective film based on fluoropolysiloxane The peeling force of the same adhesive was compared. The results are shown in Figure 1. As can be seen, the peeling force of the protective film according to the present invention is lower than that of the fluoropolysiloxane-based protective film.

The average peel force Fp of the adhesive on the protective film according to the present invention is 0.9 N / 25 mm.

The average peel force Fp of the adhesive on the commercial protective film (fluoropolysiloxane) was 1.0 N / 25 mm.

Of course, the present invention is not limited in any way to the embodiments described above, and many changes can be made to it while remaining within the scope of the appended patent applications.

Figure 1 shows the results of the peeling force of an adhesive on a protective film according to the present invention and the peeling force of the same adhesive on a commercial protective film.

Claims (29)

A silicon-based protective film for adhesives or self-adhesive components, which is characterized in that the protective film is based on polysiloxane and has a non-volatile (IDEMA standard M7-98 "Organic Contamination as Nonvolatile Residue (NVR)"",ECSS-Q-ST-70-05C" Detection of organic contamination of surfaces by infrared spectroscopy ", Seagate 20800032-001 Rev C. & 20800014-001 Rev G, Western Digital 2092-772141 Rev AD & 2092-771888 Rev AC ) Or volatile (IDEMA Standard M11-99 "General Outgas Test Procedure by Dynamic Headspace Analysis", Seagate 20800020-001 Rev N, Western Digital 2092-001026 Rev AC & 2092-771888 Rev AC) Released in the form of monomer or oligomer The measurement of the polysilicone is less than or equal to 100 ng / cm ² , preferably less than or equal to 50 ng / cm ² , preferably less than or equal to 20 ng / cm ² and even more preferably less than 10 ng / cm ² , An extractable polysiloxane content of less than 5 ng / cm ² is preferred. For example, the silicon-based protective film for an adhesive or a self-adhesive component of claim 1, which further comprises a substrate of paper, woven or non-woven or plastic. If the silicon-based protective film for an adhesive or a self-adhesive component according to claim 1 or claim 2, it has a measurement of less than or equal to 2 N / 25 mm on a Tesa ^TM 7475 adhesive measured according to the standard FTM10. Peeling force. The silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 3, which has a residual adhesion greater than or equal to 80% as measured according to the standard FTM11. The silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 4, which has a nitrogen content of less than or equal to 1 atomic% as measured according to the XPS / ESCA technology. The silicon-based protective film for an adhesive or a self-adhesive element according to any one of claims 1 to 5, which is formed of a series of polysiloxane-based layers deposited on top of each other. The silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 6, wherein each polysiloxane layer has a thickness between 5 nm and 100 nm, preferably between 10 nm and 60 nm. And even better between 10 nm and 30 nm thickness. The silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 7, which has a thickness between 5 nm and 100 nm, preferably between 10 nm and 60 nm and even better Total thickness between 10 nm and 30 nm. The silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 8, having at least one having a temperature greater than 90 °, preferably greater than 95 °, as measured on a Krüss DSA25 device, and Even better is a surface with a static contact angle of water greater than 100 °. The silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 9, having an amount of contact angle from two liquids (water and diiodomethane) as in the model of Owens and Wendt The surface energy calculated by the measurement results is less than 30 mN / m, preferably less than 25 mN / m and even more preferably less than 20 mN / m. An assembly comprising at least one silicon-based protective film for an adhesive or a self-adhesive component according to any one of claims 1 to 10, and an adhesive or a first side having an adhesive or a self-adhesive characteristic Self-adhesive components. The assembly of claim 11, wherein the protective film is attached to the first surface with the characteristics of an adhesive or a self-adhesive in the form of a peelable protective film. If the assembly of claim 11 or claim 12, wherein the adhesive element has a first surface and a second non-adhesive surface with adhesive or self-adhesive properties, the protective film is attached to the second non-adhesive surface . For example, the assembly of claim 11 or claim 12, wherein the adhesive element has a second surface with adhesive or self-adhesive properties, and a second silicon-based protective film for the adhesive or self-adhesive element is attached to the case as appropriate On the second side, the second silicon-based protective film is more specifically a second protective film according to any one of claims 1 to 10. As in the assembly of claim 11, wherein the adhesive component is a label. For example, the assembly of claim 11, wherein the adhesive element is an adhesive or a self-adhesive medical device, such as an adhesive or a self-adhesive medical dressing, such as silicification, a patch, and an adhesive electrode intended to contact the skin. A method for manufacturing a silicon-based protective film for an adhesive or self-adhesive component, the adhesive or self-adhesive component having at least one polysiloxane-based substrate intended to be placed on a paper, woven or non-woven or plastic substrate Coating, the method includes the following steps: a) moving the substrate from a substrate source in a plasma coating unit for forming the protective film to a collecting point of the protective film, b) exposing the first side of the substrate to plasma deposition in a chamber in the presence of at least one polysiloxane precursor selected from siloxanes containing cyclic feature groups, the presence of at least one An atmosphere consisting of a plasma gas whose discharge is controlled by a dielectric barrier (DBD) of the plasma gas selected from a rare gas or a mixture thereof, c) forming the polysiloxane-based coating from the polysiloxane precursor in the plasma, and d) collecting the protective film provided with the at least one polysiloxane-based coating. A method for manufacturing a silicon-based protective film for an adhesive or a self-adhesive component as claimed in claim 17, wherein the gas atmosphere in the chamber has a value of 50 ppmv or less, preferably 20 ppmv or less and even more preferably less than Or an oxygen content of 10 ppmv. The method of claim 17 or claim 18, wherein the substrate is between 10 m / min and 60 m / min, preferably between 10 m / min and 50 m / min, and preferably between 20 m / min and The substrate moves between 40 m / min, advantageously between 25 m / min and 40 m / min, and very advantageously between 30 m / min and 40 m / min. The method of any one of claims 17 to 19, wherein the gas atmosphere in the chamber is at atmospheric pressure ± 100 Pa. The method according to any one of claims 17 to 20, wherein the discharge is at a radio frequency, preferably between 0.10 W / cm ² and 10 W / cm ² , more preferably 0.15 W / cm ² , more In particular power densities between 0.2 W / cm ² or even between 0.25 W / cm ² and 0.8 W / cm ² and even more preferably between 0.35 W / cm ² and 0.7 W / cm ² The unit of area refers to the cumulative area of these electrodes. The method of any of claims 17 to 20, wherein the plasma deposition has a deposition time of 4 seconds or less, preferably 2 seconds or less and even more preferably 1 second or less. A use of a protective film according to any one of claims 1 to 10 for an adhesive element including a first surface having adhesive or self-adhesive properties. According to the application of claim 23, wherein the protective film is attached in the form of a peelable protective film in contact with the first surface having the characteristics of an adhesive or a self-adhesive. If the application of claim 23 or claim 24, wherein the adhesive element has a first surface and a second non-adhesive surface with adhesive or self-adhesive properties, the protective film is attached to the second non-adhesive surface. For example, the application of claim 23 or claim 24, wherein the adhesive element has a second surface having the characteristics of an adhesive or a self-adhesive, and a second silicon-based protective film is attached to the second surface as appropriate. The use of claim 23, wherein the adhesive element is a label. The use as claimed in claim 23, wherein the adhesive element is an adhesive medical device, such as an adhesive or a self-adhesive medical dressing, such as a silicide, a patch, an adhesive electrode intended to be in contact with the skin. For the use of any one of claims 23 to 28, it is used in a clean room.